Recanalization devices without the possibility of temperature control are used in the medical field for restoring the blood flow in blood vessels. By way of example, the blood flow can be interrupted by blood clots, more particularly thrombi, as a result of which there is a shortage of nutrients and oxygen in the downstream tissue areas. In order to restore the supply, the blood clots are removed mechanically and/or by medication.
US 2005/0085849 A1 describes such a recanalization device which enables a mechanical removal of thrombi. To this end, the device comprises a guide wire with a distal section which, when released in a blood vessel, expands radially in a spiral or screw-like manner. Using the resulting corkscrew-like structure which is positioned distally from the blood clot by means of a catheter, the blood clot is removed by withdrawing the guide wire.
A complication arising when recanalizing a blood vessel, for example after a cerebrovascular accident, is bleeding. This is connected to the fact that the necrotic regions distally from the vascular occlusion have vessels with a degenerated vessel wall. If there is a sudden blood flow during the recanalization, which accompanies the restoration of the arterial blood pressure, distal vessels may be damaged, which can lead to bleeding. This problem occurs precisely in mechanical recanalization systems which lead to a fast recanalization of the affected vessel.
The invention is based on the object of specifying a medical system which reduces the side effects during mechanical recanalization of vascular occlusions and which moreover is suitable for the effective treatment of cerebrovascular accidents. The invention is furthermore based on the object of specifying a medical catheter which is suitable for use in such a system.